Faraday rotation is a method of measuring rotation of polarized light beams by translucent specimens that has many diagnostic applications including determination of constituent concentrations in the specimens and determination of the structure of the constituents.
Conventional methods of measuring Faraday rotation require separation of the specimen rotation from a large inherent background of scattering and absorption of the light beam by the specimen. The separation is frequently accomplished by use of superconducting magnets that require liquid helium cooling to produce a high rotation within the specimen and a rotating analyzer for measurement of the polarization planar rotation.